Key matrix for a telephone handset



FIG. 1 is a front, top and right side perspective view of a key matrix for a telephone handset showing my new design;

FIG. 2 is a front elevational view thereof; and

FIG. 3 is a left side view thereof; and,

FIG. 4 is a bottom plan view thereof.

The dotted lines showing the outline of a telephone handset is for illustration purposes only and forms no part of the claimed invention. 

The ornamental design for a key "matrix for a telephone handset", as shown and described. 